Abrading device

ABSTRACT

A power operated device for abrading surfaces, which device is particularly adaptable for use in the repair of vehicle bodies, wherein epoxy material is used to fill body dents and irregularities. The device may be adjusted to abrade the surface of the repair material without marring the finish of the surrounding area, and the surface of the abraded material is so abraded as to have the exact contour as the surface originally had, whether the surface is concave, convex or planar.

United States Patent Waters 5] Oct. 28, 1975 ABRADING DEVICE 2,810,240 10/1957 Davis et al. 1. 51/170 PT [76] Inventor: Warren W. Waters, Rte. 3, Box

435 Wi Falls, Tex, 7 30 Primary ExaminerJames L. Jones, Jr. 1 A1 A 1 -W l dD.K'th Filed: Dec. 1974 torney, gen or Fzrm ay an e1 [21] Appl. No.: 536,020 [57] ABSTRACT 52 US. Cl 51/170 PT A F? i devce for abradng furfaces i 2 device is partlcularly adaptable for use in the, repair of [51] Int. Cl. B24B 23/00 vehicle bodies wherein 6 OX material is used to fill [58 Field of Search 51/170 PT, 170 EB, 170 R, .P y

51/l76 body dents and irregularmes. The device may be adjusted to abrade the surface of the repair material without marring the finish of the surrounding area, [56] References Clted and the surface of the abraded material is so abraded UNXTED STATES PATENTS as to have the exact contour as the surface originally 1,404,342 1/ 1922 Clarke 51/170 PT had, whether the surface is concave, convex or planar. 1,841,787 l/l932 Carter 2,069,700 2/1937 Emmons 51/170 PT 12 Claims, 17 Drawing Figures 2 58 I I [O iz 22 1" 20 22 U03. Patsnt Oct. 28; 1975 Sheet 1 of3 3,914,905

US. Patent Oct. 28, 1975 Sheet 3 of3 3,914,905

FIG. l6

ABRADING DEVICE This invention relates to abrading devices and more particularly to abrading devices for smoothing and contouring epoxy material and the like which has been used to fill dents in vehicle bodies or for other sheet metal work, to fill in and repair dents and scars, so that the contoured fill material will match the contour of the adjacent areas. The abrading of such work is usually done free hand with rasps and motor driven sanders, such as disc sanders, and the contour eyeballed for matching accuracy to the adjacent areas. In the case of automobiles and other vehicles, the reverse matching of contours on opposite sides of the vehicle obviously required great skill, especially when different contours were encountered.

PRIOR ART Various proposals have been made heretofore for abrading or sanding devices, but these, for the most part, would accommodate contours of a general character and could not be adjusted to match other contours without visual reckoning. The guides and adjust ments as proposed by the prior art were awkward to use and quite time consuming.

Investigation of the prior art reveals the following patents:

No. l 404 342 Clark Jan. 24, 1922 No. l 480 285 Moore Jan. 8, 1924 No. 1 841 787 Carter June 9, 1932 No. 2 810 240 Davis et al Oct. 22, 1957 N0. 3 789 552 Bradbury et al Feb. 5. I974 OBJECTS OF THE INVENTION An object of this invention it to provide a motor driven abrading device which will make possible the accurate abrading of contours to match the contours of the surface being abraded.

Another object of the invention is to provide a variable contour guide for a drum type abrading device which may be readily adjusted to various contours by a single means.

Still another object of the invention is to provide, for a drum type abrading device, a shield which will shield adjacent areas from the drum, while a limited abrading surface of the drum is being used.

A further object of the invention is to provide a single attachment for attaching a sheet of abrasive material to a drum of the abrading device.

Yet another object of the invention is to provide a means for continuously urging an abrasive sheet of material into engagement with a drum of the abrading device during the operation thereof, when the abrasive sheet is attached to the periphery of the drum by an adhesive.

Still a further object of the invention is to continuously withdraw, by suction, dust from the work surface being abraded, by passing air containing such dust axially through the interior of the drum into a collection receptacle.

Another object of the invention is to provide an abrasive device with a guide to engage the edge of a curved surface to enable an operator to readily follow the con tour of the curved surface.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of the abrading device, with parts broken away and with parts removed, and parts shown in full and in dashed outline, to show alternate positions of the adjustment lever and the drum;

FIG. 2 is a front elevational view of the avrading device as shown in FIG. 1, with parts broken away and with parts shown in section to bring out the details of construction;

FIG. 3 is a fragmentary view of an intermediate portion of the abrading device, showing the side opposite that shown in FIG. 1, and showing the dust receiving bag in dot-dash outline;

FIG. 4 is a composite, side elevational view of the abrading device with the contour guide thereon and showing the contour guide in full outline adjusted to a plane position and in dashed outline adjusted to a concave position and showing the adjustment lever in full outline for adjusting to a plane position and in dashed outline for adjusting to a concave position, the third position of the lever being shown in this FIG. shows an adjustment center line for moving the lever which adjusts the contour guide into a convex position;

FIG. 5 is a front elevational view of the front end only of the composite abrading device shown in FIG. 4, with parts broken away and with parts shown in section;

FIG. 6 is a fragmentary side elevational view ofa cam action adjustment means of the cam action which bindingly engages the contour adjustment lever with the frame of the abrading device;

FIG. 7 is a fragmentary view from the bottom of the rear end portion of the abrading device, with parts broken away and with parts shown in section to bring out the details of construction;

FIG. 8 is a perspective view of a spring biased roller assembly, such as shown in FIG. 2;

FIG. 9 is a perspective view of the abrasive sheet engaging and tensioning member, with parts broken away and with parts shortened and shown in section to bring out the details of construction;

FIG. 10 shows an abrasive sheet engaging member to retain an end of the abrasive sheet against relative movement with respect to the drum;

FIG. 11 is a side elevational view of a modified form of the abrading device, showing in full outline, the abrading guide attachment attached thereto, and showing in dashed outline, a surface to be abraded;

FIG. 12 is a sectional view taken on the line 12-12 of FIG. 11, looking in the direction indicated by the arrows, of the abrading guide attachment;

FIG. 13 is a side elevational view of the modified form of the abrading device, showing a modified form of the guide, the guide being shown in full outline and attached to the abrading device by a toggle action latch;

FIG. 14 is a sectional view taken on the line 14-14 of FIG. 13, looking in the direction indicated by the arrows;

FIG. 15 is a side elevational view of an abrading device which utilizes and air motor for power, parts being broken away and parts being shortened and shown in section to show the construction;

FIG. 16 is a front elevational view of the abrading device, showing an air motor thereon, the contour guide of the abrading device not being shown, other parts being broken away and parts being shown in dot-dash outline to bring out the details of construction;

FIG. 17 is a fragmentary elevational view, partly in section, ofone of the vanes, showing slots therein to receive a resilient arm and a resilient latching arm.

DETAILED DESCRIPTION OF THE INVENTION With more detailed reference to the drawings in which like reference characters designate like parts in the several views thereof, and referring particularly to FIGS. 1 through 3, the abrading device is designated generally by the numeral 10, which device comprises a main support frame means 12, which frame is generally the shape of an inverted U in cross-section, and has a top wall 14 and a pair of side walls 16 and 18. A first handle 20 is fixedly attached to the rear of the main support frame means 12, and a second handle 22, generally the shape of an inverted U, has legs 24 and 26 which straddle the front portion of the main support frame means 12 and are pivotally attached thereto by axially aligned pivot screws 28 which extend through the respective legs and into the main support frame means 12.

An abrasive drum 30 extends between the walls 16 and 18 of the inverted U-shaped main support frame means 12. A shaft 29 extends through an axial passage in the abrading drum 30, which drum and shaft are interconnected in driving relation. The shaft 29 extends outward through an arcuate slot 32 in the respective walls 16 and 18 and through a hole 34 in each of the legs 24 and 26, whereby the drum is supported by a bearing on legs 24 and 26, thus the drum is supported on the arcuately movable U-shaped second handle 22, which raises and lowers the drum within the arcuate slots 32.

A sprocket 36 is secured to one end of shaft 29 in driven relation and the other end of the shaft 29 is threaded to receive a threaded nut 38 thereon to maintain the shaft 29 against relative movement with respect to second handle 22. Arcuate movement of the handle 22 will cause the shaft 29 and abrading drum to be moved relative to main support frame means 12 to cause the drum 30, having a band of abrasive material 66 thereon, to engage the surface being abraded in accordance with the adjustment of the drum 30 by the second handle 22.

A motor means 40 is mounted on the rear portion of the main support frame means 12 and has a drive shaft 42 extending through the wall 16. A drive sprocket 44 is fixedly secured to shaft 42 and is rotatable therewith and is in driving alignment with sprocket 36 on shaft 29. A drive chain 46 surrounds sprockets 36 and 44 in driving relation to enable the motor means 40 to drive through sprocket 44 and sprocket 36, which in turn, drives the drum 30 which is fixedly secured to shaft 29.

A chain guard 48 is attached to main support frame means 12 by screws 50 to cover chain 46 and sprockets 36 and 44.

A bolt 52 extends through the legs of the second handle 22 and is threaded at one end thereof, as indicated at 54. A threaded nut 56, having a thumb lever integral therewith and extending therefrom, is rotated in one direction on the threaded end 54 of bolt 52 so as to bindingly engage the legs 24 and 26 against main support frame means 12 to frictionally lock the second handle in place to maintain the drum 30 in fixed relation to the surface on which the main support frame means 12 is seated. By moving the thumb lever 58 iin the opposite direction, the nut is loosened to permit relative movement of the second handle 22 about the screws 28 as a axis to a desired position relative to the surface being abraded, whereupon the thumb lever 58 is moved arcuately to tighten the nut 56 to second handle 22 to hold the rotatable drum 30 mounted thereon in adjusted fixed relation with respect to the surface being operated upon.

Referring to FIGS. 3, 9 and 10, a longitudinal opening 60 is formed in the periphery of the drum 30 for receiving opposite ends 62 and 64 of a strip of flexible, abrasive material 66, such as emery cloth, abrasive screen material, sandpaper and the like, therethrough, with one end of the strip being engaged with a toothed hinge-like fastener, designated generally at 72. One portion 68 of the fastener 72 is welded along a sharp edge of the longitudinal slotted opening 60 in drum 30, with one of the movable hinge segments being an outwardly extending arm 84 thereon, with the arm 84 on movable segment 70 receiving a re-entrant portion 86 of resilient wire 80 therebelow. The resilient wire 80 passes through hinge portions 70 and 75 as the axis and has an outwardly extending resilient arm 82 of the spring wire biased within a slot 94 in one of the vanes 88 positioned within drum 30 to form a spiral exhaust fan, designated generally at 90. The portions 75 of the hingelike fastener 72 are integral with hinge portions 68, which portion 68 is welded to the edge of drum 30, FIG. 10. This enables the flat, holddown portion 76, having saw toothed edge 78 thereon, to be moved arcuately about the axis of resilient wire 80 to open the flat portion 76 for insertion of the end 64 of the strip of flexible abrasive material 66 thereinto and over the edge 77 which forms one side of the longitudinal slot 60. Upon release of outwardly extending arm 84, the saw toothed edge 78 will hold the strip of flexible, abrasive material 66 in place. When the flexible, abrasive strip of material is wrapped around the drum 30, the end 62 of the strip 66 will be directed into the tubular member 96 and through a slot 98 formed therein, and with the resilient wire, designated generally at 100, having a portion 102 extending therethrough, with a re-entrant portion 104 extending into groove 108 in the tubular member 96, so upon movement of an outwardly extending resilient latching arm 110 of wire and engaging the portion in a slot 95 of vane 88 will enable the flexible strip of abrasive material 66 to be drawn in taut relation around drum 30.

Upon the resilient arm I10 exerting torsion on tubu lar member 96, which is fitted within a concave seat 97 within drum 30 which seat has a curvature of more than degrees, the edge of the slot 98 will engage the flexible, abrasive strip 66 as the resilient latching arm 110 maintains a torsion on the tubular member 96 to cause the abrasive strip 66 to fit snugly around the circumference of the drum 30. The resilient latching arm 110 engages in slot 95 to maintain constant torsion.

The flexible, abrasive strip may be removed by moving resilient arm 110 out of slot 95 and removing the end 62 of the strip 66 from slot 98, the abrasive strip is loosened, then by depressing resilient latching arm 84, the abrasive strip 66 may be removed for replacement with another strip, in the manner set out above. In operating the abrading device, the drum 30 rotates in a counter-clockwise direction, when viewed in FIG.

I, as indicated by the arrow. This enables the operator to push against the work without the abrading element digging into the surface being abraded, tending to pull the device from the hands of the operator.

The drum 30 is hollow except for a plurality of spiral vanes 88 and an axial hub (not shown) to which hub the spiral vanes are connected, as well as to the interior cylindrical portion of the drum to form an axial spiral fan 90 to withdraw the dust from the surface being abraded and to direct the dust outwardly through openings 112 into a dust collection bag 116, as will best be seen in FIGs. 2 and 3. The bag 116 is connected with conduit 114, which conduit is connected to wall 16 and surrounds openings 112 therein.

The springs 130 are pre-tensioned by the rotation of shaft 120 so the squared portion 123 will fit within a squared opening in wall 18 so as to cause the elastomer roller 126 to be in rolling, contact relation with the abrasive strip 66. The shaft 120 has a head 122.

The elastomer roller 126 serves two functions, first, the adhesive may be applied to the abrasive strip before the strip is placed on the drum 30, and the roller 126 will cause the abrasive strip to be rolled into adhesive relation with the drum at all times, with the minimum anchoring of the ends of the abrasive strip. Second the elastomer roller will aid in cleaning the abraded particles from the abrasive strip as the abrasive strip 66 and the roller 126 are rotatedffhe elastomer roller 126 has a shaft 128 therein. The shafts 120 and 128 each have diametrical holes therethrough to receive the respective ends of torsion springs 130.

sEcoNo FORM o5 THE INVENTION In the form of the invention as shown in FIGS. 1, 2, 3 and 8, a shaft lextends through walls 16 and 18 of the main support frame means 12. The shaft 120 is in the form of a carriage bolt and has ahead 122 thereon with a squared shoulder portion 123 therebelow to complementally engage a squared opening in the wall 18 of the main support frame means 12. A shaft 120 extends therethrough and has a nut 124 on the opposite end thereof to maintain the shaft 120 against longitudinal movement. The shaft 120 has a pair of spaced apart parallel holes formed diametrically therethrough, each which hole receives a torsion spring 130, as will best be seen in FIG. 8. Each torsion spring is substantially S-shaped and extends outward and passes through respective holes in a shaft 128 on which an elastomer roller 126 is mounted.

The springs 130 are pre-tensioned by the rotation of shaft 120 so the squared portion 123 will fit within the squared opening in wall 18 so as to cause the elastomer roller 126 to be in rolling contact relation with the abrasive strip 66.

The elastomer roller 126 serves two functions; first. an adhesive "may be applied to the abrasive strip before the'strip is placed on the drum 30, and the roller 126 will cause the abrasive strip to be rolled into adhesive relation with the drum at all times, with a minimum of anchoring of the ends of the abrasive strip; second, the elastomer roller will aid in the cleaning of the abrasive particles from the abrasive strip, as the abrasive strip 66 and the roller 126 are rotated.

THIRD FORM OF THE INVE T O The form of the invention, as shownin FIGS. 4, 5 and 7 utilizes the form of the invention as shown in FIGS.

1, 2 and 3, andthe same numerals are applied to the parts which arecommon to both forms of the invention.

The form of the invention as shown in FIGS. 4, 5, and 7 discloses a detachable contour guide 200 which is attached to the abrading device 10. The main support frame means 12 has a second support frame means 202 connected thereto, which comprises a pair of side walls 204, the front portion of which have the rear edges thereof shaped to be complementary with the front edge 206 of the respective walls 16 and 18, of the abrading device 10. The walls 204 are spaced apart the same distance as the walls 16 and 18 so the edges 205 and 206 will be in abutting relation, when assembled as shown in FIG. 4. Axially aligned pins 208 extend outward from the respective side walls 16 and 18 to be slidably received in angulated slots 212 formed in said second support frame means 202. The front top wall portion 214, which extends between side walls 204, has an upstanding lug 216 secured thereto, which lug is engageable by a loop of toggle action latch 210 to bring the edges 205 and 206 together, when in one position to secure the contour guide 200 thereto and to allow the latch 210 to release the front end of the guide 200, when it needs to be removed from the abrading device 10.

The rear edge of the top wall 214 abuts with the front edge of top wall 14 when the pins 208 are located in the angulated slots 212 in the second support frame means 202 and the guide 200 is rotated about the axis of pins 208 until edges 205 and 206 abut and the toggle action latch 210 is engaged with lug 216 to hold the guide 200 in place. The reverse proceedure is followed to release the guide from the abrading device. A U-shaped third handle means 218, having a knob-like hand-hold 219 thereon, allows the third handle means 218 to be moved about the axis of shaft 220 to positions A, B or C. as shown in FIG. 4. The shaft 220 has a lever-nut mechanism 222 which threadably engages the end of shaft 220, so when the lever is moved into one position it is in binding engagement with walls 204 to hold the U-shaped third handle means 218 in adjusted position.

The opposite end of the shaft 220 has a head 223 thereon, as shown in FIG. 6, which head of the shaft is positioned between a pair of abutments 225 secured to one of the plates 227 which is held against rotation by a screw 229. The head 223 of shaft 220 may be changed to different positions between abutments 225 so that slight movement of the lever of thumb lever-nut mechanism 222 will bindingly engage the third handle means 218 with the side walls 204, thereby causing each of a pair of apertured linkage means 224, which extend between outwardly extending, apertured arms 226 on third handle 218. The respective apertured flanges 230 are moved by the linkage means 224, having screw fastening means 228 and 230A passing through the apertured linkage means and through the apertured flanges 230. This enables the third handle means 218 to move the flexible guide plate means 232 from the full outline position, as shown in FIG. 4, to the dashed outline position, as shown in FIG. 4 or FIG. 15. Upon movement of the forward portion of the flexible guide plate means 232, a rear flexible guide plate third handle means 218 a pair of side plates 240, which are attached to adjacent ends offlexible plates 232 and 234, will pivot about pivot screws 242 to form a pivot means to cause the flexible guide plate means 232 and 234 to form a concave arrangement when the adjustment third handle is moved to position B. FIG. 4, which will enable the operation ofa convex surface of the particular contour to which it is adjusted.

With the third handle means 218 in position A, the flexible plate means 232 and 234 will be held in plane position for operating on a plane surface.

The plate 232 and the plate 234 are perforated, as indicated at 233, and are formed either of tempered aluminum or other flexible, resilient metal, so as to give maximum flexibility and curvature without metal fatigue.

A front cross plate 244 is secured to the rear end of plate 232, as by means of screws, welding, or the like, and plate 234 is secured at its forward end to a cross plate 246, which plates are spaced apart to permit a portion of the abrading drum 30 to project therethrough, as is best seen in FIGS. 4, 7 and 15. When the third handle means 218 is shifted to position C, as shown in FIG. 15, the arm 226 is rotated in a counterclockwise direction to force the front end of plate 232 upward, thereby rotating the plate 240 is a counterclockwise direction, which will force the leading edge of plate 240 downward and the reentrant means portion 236 forward to form a convex surface for guiding the abrading device on a concave surface. Locating the third handle means 218 at various positions between positions A and C provide selected convex contours of the guide plate 232 and the guide plate 234.

The main support frame means 12 has indicia 237 thereon to enable the gauging of the setting of the depth or projection of the drum 30 below the opening 13 in contoured guide 240. This enables a further handle 22 to be set anywhere from zero depth to the maximum depth and to come back to the same setting without trial and error adjustments.

The plate 227 has indicia markings 235 thereon to register with a complementary portion of the third handle means 218 or a pointer thereon, so that the flexible plate 232 and the flexible plate 234 can be set to the desired contour, then, if it becomes necessary to change, will come back to the original setting without trial and error adjustments.

By adjusting the second handle 22 to the desired position, the drum 30 may be made to project through the opening 13 between adjacent ends of flexible guide plates 232 and 234, which drum 30 will be positioned between the side plates 240 and the cross plates 244 and 246, which cross plates are disposed on the respective ends of flexible guide plates 232 and 234, as will best be seen in FIG. 7. The arcuate movement of further handle 22 shifts the drum shaft 29 arcuately in slot 32, as shown in positions D and .E, in full and in dashed outline respectively in FIG. 1, relative to the abrading device and contour guide assembly 200, as shown in FIG. 4.

FOURTH FORM OF THE INVENTION With reference to FIG. 11, the abrading device 10 is shown with a edge guide assembly 300 attached thereto. This assembly 300 comprises a U-shaped bracket 302 with a slot 304 in the rear end of each wall The walls 306 are spaced apart to straddle walls 16 and 18, and extend forwardly of abrading drum 30 to enclose the forward end of the abrading drum by a wall 336, but leaving an opening 337 between the lower edge of the front wall 336 and the forward end of the bottom wall 307 forming a guide shield means. The upper portion of the front wall 336 has a lug 317 thereon to receive the loop of toggle action latch 210 so as to bindingly engage the edge of wall 336 and wall 338, with the forward edge 206 of the means support frame means 12. This encloses the abrading device, except for the bottom opening, so that the fan will exhaust the abraded particles into a dust bag 116. With the transversely aligned pins 208 within slot 304 and with the toggle action latch in closed position, as shown in FIG. 11, the device may be used on concave contours and guided around the edges of a work piece, as shown in dot-dash outline in FIG. 11.

The guide means designated generally at 314 has an apertured flat guide plate 316 which has a downwardly curved concavo-convex guide lug 318 in the forward end thereof. The flat guide-plate 316 is apertured to receive a bolt 320 therethrough, which bolt has a wing nut 324 thereon. A tang 326 is integral with the flat guide plate 316, which tang extends into longitudinal slot 310 to hold the guide means 314 in proper slidable relation with respect to the bottom of the abrading device. The guide assembly is detachably secured to the abrading device 10 by bringing the notches 304 into engagement with axially aligned pins 208 and swinging the forward end of the guide shield means upward into the position as showin in FIG. 11 and engaging the toggle latch 210 with lug 317 on the forward end of wall 336.

The guide means 314, when properly set in the desired position, is particularly useful in abrading surfaces along an edge of a work piece, when a reverse curve (convex) surface is being abraded, such as a surface on a vehicle, or a body edge, such as a fender skirt. Such arrangement is shown in dot-dash outline in FIG. 11, and where a fender skirt is shown in phantom and is designated by the numeral 330. The concave surface is designated by the numeral 332 and the edge of the skirt as 334. 4

The edge of the fender skirt 334 fits into a cavity defined by the curved portion of the guide lug 318 and the abrading drum 30. The abrading device is moved along the edge 334 which may be defined by an are lying in a plane parallel to the abrading drum axis and perpendicular to the flat portion 316 of the guide plate. It should be noted that when the guide lug 318 takes the position as show-n in FIG. 11, the cavity for receiving the edge 334 will be defined by the curved portion of the guide lug 318 and the bottom wall 307 of the bracket 302. This particular guide means 314 enables uniform, accurate work to be performed where an edge is present to guide the abrading device along the desired course.

FIFTH FORM OF THE INVENTION Reference is made to FIGS. 13 and 14 which show another modification of the invention. In this form of the invention a generally U-shaped guide shield means, designated generally at 400, is attached to the abrading device 10. The walls 402 and 403 of the Ushaped guide shield means 400 are received by walls 16 and 18 of the support frame 12, and each of the walls 402 and 403 has an angulated slot 404 formed therein to interengage with axially aligned pins 208 in the respective walls 16 and 18.

The walls 402 and 403 extend forward and have a closed forward end wall 407 thereon, with an upstanding lug 406 on the upper side thereof to interengage with a loop on toggle action latch 210 so as to draw the walls 402 and 403 into binding engagement with the edge 206 of walls 16 and 18 so as to draw the edge 405 of walls 402 and 403 into binding engagement with the edge 206 of walls 16 and 18. The forward end wall 407, together with walls 402 and 403 form a closed chamber to partially surround abrading drum 30, so that the suction of the fan 90 will withdraw dust and abraded particles created by the operation of the abrading drum 30 through opening 410, in the bottom wall 408, and to direct this into dust collector bag 116, in the manner described and shown for the other forms of the invention.

The U-shaped guide shield means 400 is wider than the abrading drum 30, except for the lower portion thereof, as will best be seen from FIG. 14, and the drum 30 will be retracted until the portion W thereof is shielded against abrading relation with the portion of the surface not being abraded, with the edge of the drum, as indicated at 31, extending outwardly through the opening 410 to enable either edge 31 to be used to abrade in close places, without marring the finish on the portions not being abraded.

By having the edges 31 of the drum 30 extending outwardly, as indicated at w, this much of the abrading drum will be exposed to abrade the surface in a corner of 90 or more, without abrading adjacent surfaces. Adjustment of the abrading drum 30 by means of further handle means 22, is had as set forth in the aforementioned forms of the invention. The amount of exposed surface of the drum may be regulated, including extending the drum through the opening 410 to perform surface abrading with the portion of the drum shielded by the planar surface indicated at W. It is to be understood that the toggle action latch may be released and the U-shaped guide or shield 400 may be instantly removed by swinging the unit 400 downward about the axis of pins 208 and moving the shield rearwardly to disengage the device from the angulated slots 404.

The portion W is planar in cross section, from wall 402 to wall 403, for a portion of the width of the drum 30 and is then curved upwardly to merge with walls 402 and 403. Obviously the curvature of the merging bottom planar portion W with the walls 402 and 403 may be curved in any manner desired so as to expose as much of the abrading drum as required.

SIXTH FORM OF THE INVENTION The form of the invention, as shown in FIGS. and 16 depicts an air motor driven abrading unit, designated generally by the numeral 500. Air motor 502 is connected in driving relation with the abrading drum 30, in a manner similar to that shown and described for the aforementioned forms of the invention. The air motor which drives the abrading unit 500 has a first handle 504, which has an air valve operated mechanism therein, with a lever 506 to operate the valve to direct air from a source of supply under pressure through an air hose connector 508 to and through the valve (not shown) within handle 4 to air motor 502. With the air motor exhausting into an air receptacle 510, which has longitudinally spaced apart angulated holes 512 formed in the lower side thereof so that the air discharged from the motor will discharge into the receptacle 510 and through holes 512 substantially tangentially to drum 30 at the point where the abrading device is acting upon a surface being abraded. Whereupon, the blast of air from the holes 512 will blow the abraded particles and dust from the surface, and with the fan drawing the dust and particles therethrough to be discharged into dust collector bag 116.

The air motor 502 serves a dual purpose, that of cleaning the surface being abraded, and of furnishing the power for the unit, however, it is to be understood that the aforementioned forms of the invention, which utilize electric motors, may have fans therein to cool the motors and to exhaust the air through holes 512 in the same manner as described for the air motor, and by showing the air exhaust holes with the form of the invention designated as the sixth form, with the unit being designated at 500, this is representative and not to be considered as limiting the device to air motors only.

All the attachments and accessories shown and described for this form of the invention, including the adjustable features are applicable to this form of the invention, are the same as for those forms shown and de scribed above, or, the device may be used without attachments, in a manner similar to that shown in FIG. 1.

Whenever the term means" is employed in the claims, this term is to be interpreted as defining the corresponding structure illustrated and described or the equivalent thereof.

What is claimed is:

l. The combination of a rotatable abrading device guide assembly comprising;

a. main support frame means,

b. an abrading drum rotatably mounted on said main support frame means,

c. motor means carried by said main support frame means for driving said drum,

d. guide plate means,

1, said guide plate means having an opening formed therein intermediate the ends thereof, for receiving said drum,

2. a second support frame means,

3. pivot means pivotally connecting said guide plate means, at a position intermediate the ends thereof, to said second support frame means,

. linkage and re-entrant means carried by said second support frame means and operably connected to each end of said guide plate means for allowing movement of said ends relative to said main support frame means, and for supporting said ends during an abrading operation,

5. single manual handle means operatively connected to said guide plate means and to said second support frame means for pivoting said guide plate means about the pivotal connection thereof to said second support frame means, thereby effecting movement of said ends relative to said main support frame means to change the position of said guide plate means,

. said pivotal connection of said guide plate means to said second support frame means and to said linkage and re-entrant means allowing movement of said ends of said guide plate means relative to said main support frame means and said guide plate means relative to said main support frame means and said pivot means for pivoting said guide plate means, which guide plate means is so constructed and arranged as to effect the contour of the lower surface thereof, which is normally planar.

2. The combination as defined in claim 1; wherein said manually operated handle means for pivoting said plate means comprises,

1. a handle pivotally mounted on said second support means and having a portion thereof operatively connected to one end of said guide plate means.

3. The combination as defined in claim 1; wherein said linkage and re-entrant means for allowing movement of said ends of said guide plate means relative to said main support frame means includes;

1. a cross shaft fixed to said main support frame means,

2. one of said ends of said guide plate means being slidably connected to said cross shaft.

4. The combination as defined in claim 3; wherein said pivot means for pivoting said guide plate means comprises;

bination comprises;

said main support frame means and a second support frame means,

1. said main support frame means carries said drum and said motor driving means,

2. said second support frame means carries said handle means, said fixed shaft and said pivot means for pivotally attaching said guide plate means to said second support frame means,

fastening means carried by said second support frame means and said main support frame means for detachably cooperating to secure said frame means together.

The combination as defined in claim 2; wherein said guide plate means is flexible,

said manually operated handle means is connected to said flexible guide plate means to effect movement of said ends of said guide plate means relative to said second support frame means to change the contour of said guide plate means so upon movement of said handle means said normally planar, flexible guide plate means will have the lower surface thereof concave or convex. 8. The combination of a rotatable abrading device 5 comprising;

a. a main support frame means,

b. an abrading drum rotatably mounted on said main support frame means,

0. motor means carried by said main support frame means for driving said abrading drum,

cl. said main support frame means having an opening formed in the lower portion thereof,

1. a segment of said abrading drum extending through said opening,

2. an eccentrically mounted further handle means on said main support frame means and being operatively connected to said drum for raising and lowering said drum,

3. locking means on said further handle means to hold said further handle means in a selected position relative to said main support frame means.

9. A rotatable abrading device as defined in claim 8;

wherein a. said main support frame means has a guide shield means attached thereto, which guide shield means has a plane intermediate lower surface with rounded corners,

b. said guide shield means having an opening formed therein and extending thereacross and into said rounded corners,

c. said abrading drum, which is mounted on said main support frame means, having the ends thereof extending outward from said guide shield means, when in one position, with a portion of the drum, intermediate the ends thereof being shielded from contact with the surface being abraded, when in another position.

10. A rotatable abrading device as defined in claim 9; wherein a. said handle means has indicia associated therewith,

b. said handle means being selectively movable relative to said indicia,

c. locking means associated with said handle means and and with said second support frame means to lock said handle relative to said second support frame means when said handle means is in a selected position with respect to said indicia.

11. A rotatable abrading device as defined in claim 8; wherein a. said motor means carried by said main support frame means for driving said abrading drum is an air motor,

1. said air motor having discharge outlets extending therefrom to a position near the surface being abraded so as to clean the surface being abraded.

12. A rotatable abrading device as defined in claim 8; wherein a. said guide shield means adjustably mounts a guide means on the lower side thereof, which guide means projects forward and is curved downwardly and forwardly near the abrading drum to enable the abrading device to be held in guided relation with an edge being abraded. 

1. The combination of a rotatable abrading device guide assembly comprising; a. main support frame means, b. an abrading drum rotatably mounted on said main support frame means, c. motor means carried by said main support frame means for driving said drum, d. guide plate means,
 1. said guide plate means having an opening formed therein intermediate the ends thereof, for receiving said drum,
 2. a second support frame means,
 3. pivot means pivotally connecting said guide plate means, at a position intermediate the ends thereof, to said second support frame means,
 4. linkage and re-entrant means carried by said second support frame means and operably connected to each end of said guide plate means for allowing movement of said ends relative to said main support frame means, and for supporting said ends during an abrading operation,
 5. single manual handle means operatively connected to said guide plate means and to said second support frame means for pivoting said guide plate means about the pivotal connection thereof to said second support frame means, thereby effecting movement of said ends relative to said main support frame means to change the position of said guide plate means,
 6. said pivotal connection of said guide plate means to said second support frame means and to said linkage and re-entrant means allowing movement of said ends of said guide plate means relative to said main support frame means and said guide plate means relative to said main support frame means and said pivot means for pivoting said guide plate means, which guide plate means is so constructed and arranged as to effect the contour of the lower surface thereof, which is normally planar.
 2. a second support frame means,
 2. an eccentrically mounted further handle means on said main support frame means and being operatively connected to said drum for raising and lowering said drum,
 2. said second support frame means carries said handle means, said fixed shaft and said pivot means for pivotally attaching said guide plate means to said second sUpport frame means, b. fastening means carried by said second support frame means and said main support frame means for detachably cooperating to secure said frame means together.
 2. one of said ends of said guide plate means being slidably connected to said cross shaft.
 2. The combination as defined in claim 1; wherein a. said manually operated handle means for pivoting said plate means comprises,
 3. The combination as defined in claim 1; wherein a. said linkage and re-entrant means for allowing movement of said ends of said guide plate means relative to said main support frame means includes;
 3. locking means on said further handle means to hold said further handle means in a selected position relative to said main support frame means.
 3. pivot means pivotally connecting said guide plate means, at a position intermediate the ends thereof, to said second support frame means,
 4. linkage and re-entrant means carried by said second support frame means and operably connected to each end of said guide plate means for allowing movement of said ends relative to said main support frame means, and for supporting said ends during an abrading operation,
 4. The combination as defined in claim 3; wherein said pivot means for pivoting said guide plate means comprises; a. handle means pivotally mounted on said second support frame means and having a portion thereof operatively connected to the other end of said guide plate means.
 5. The combination as defined in claim 4; wherein a. said operable connection between said handle means and said other end of said guide plate means is linkage means pivotally connected to said handle means and to said other end of said guide plate means.
 5. single manual handle means operatively connected to said guide plate means and to said second support frame means for pivoting said guide plate means about the pivotal connection thereof to said second support frame means, thereby effecting movement of said ends relative to said main support frame means to change the position of said guide plate means,
 6. The combination as defined in claim 4; which combination comprises; a. said main support frame means and a second support frame means,
 6. said pivotal connection of said guide plate means to said second support frame means and to said linkage and re-entrant means allowing movement of said ends of said guide plate means relative to said main support frame means and said guide plate means relative to said main support frame means and said pivot means for pivoting said guide plate means, which guide plate means is so constructed and arranged as to effect the contour of the lower surface thereof, which is normally planar.
 7. The combination as defined in claim 2; wherein a. said guide plate means is flexible, b. said manually operated handle means is connected to said flexible guide plate means to effect movement of said ends of said guide plate means relative to said second support frame means to change the contour of said guide plate means so upon movement of said handle means said normally planar, flexible guide plate means will have the lower surface thereof concave or convex.
 8. The combination of a rotatable abrading device comprising; a. a main support frame means, b. an abrading drum rotatably mounted on said main support frame means, c. motor means carried by said main support frame means for driving said abrading drum, d. said main support frame means having an opening formed in the lower portion thereof,
 9. A rotatable abrading device as defined in claim 8; wherein a. said main support frame means has a guide shield means attached thereto, which guide shield means has a plane intermediate lower surface with rounded corners, b. said guide shield means having an opening formed therein and extending thereacross and into said rounded corners, c. said abrading drum, which is mounted on said main support frame means, having the ends thereof extending outward from said guide shield means, when in one position, with a portion of the drum, intermediate the ends thereof being shielded from contact with the surface being abraded, when in another position.
 10. A rotatable abrading device as defined in claim 9; wherein a. said handle means has indicia associated therewith, b. said handle means being selectively movable relative to said indicia, c. locking means associated with said handle means and and with said second support frame means to lock said handle relative to said second support frame means when said handle means is in a selected position with respect to said indicia.
 11. A rotatable abrading device as defined in claim 8; wherein a. said motor means carried by said main support frame means for driving said abrading drum is an air motor,
 12. A rotatable abrading device as defined in claim 8; wherein a. said guide shield means adjustably mounts a guide means on the lower side thereof, which guide means projects forward and is curved downwardly and forwardly near the abrading drum to enable the abrading device to be held in guided relation with an edge being abraded. 